THE YOUNG 



NATURALIST. 



101 



the petals and gradually extending 

 downwards, the base or claw longest 

 retains the original colour. As illus- 

 trating this progressive change the 

 bright yellow buttercups have in the 

 white water crowfoot (Ranunculus 

 aquatilis), advanced to the pure white 

 stage, but even in these the base of 

 the claw of the petal is often seen to 

 retain the primitive yellow hue. Or 

 take the familiar daisy, in which the 

 central florets remain of the original 

 yellow colour, the ray florets have pro- 

 gressed to pnre white, whilst in many 

 of these the pink stage has commenced 

 and the back and tips of the petals are 

 suffused with the inimitable blush of 

 "the modest crimson-tipped flower." 

 A further step in the ascending scale 

 may be noted in the common milkwort 

 (Poly gala), where white, pink, and 

 blue forms are equally common. In 

 the highly mutable pilewort we therefore 

 see by the fading petals a transitional 

 step to the white stage, and the still 

 more advanced purplish bloom on the 

 back of the petals, indicates a yet 

 further progressive movement already 

 begun. When once a flower has taken 

 the initial step in this ascending scale 

 of colour the further stages are easy. 

 Thus florists know that almost any 

 desirable shade is attainable in flowers 

 which have once progressed to the 

 fundamental colour. The difficulty is 

 to get them to overstep the line to a 

 fresh series, thus in the primitive roses, 



all shades of yellow, white, pink, crim- 

 son are common enough, but so far 

 they have obstinately refused to march 

 on to the cerulean bine ; whilst in the 

 more specialised hyacinth every varia- 

 tion of colour, from creamy white to 

 deep blue is attainable. Of course it 

 is quite possible for any, even the most 

 advanced colour, to become so fixed in 

 an individual as to seem unalterable, 

 thus we have the unchangeable azure 

 of the spring gentian (gentiana verna), 

 the brightest arid most constant blue 

 of any of our native plants, but the 

 natural order GentianacecB exhibits 

 every gradation in the whole gamut 

 of colour. The natural reversion of 

 colour is also strong corroborative 

 proof of this theory, thus there is 

 scarcely, if at all, a native flower which 

 has advanced beyond the yellow stage 

 but what wild white specimens have 

 been seen, and in extremely variable 

 cultivated plants, such as the crocus, 

 the highly specialised purple and white 

 varieties rapidly revert to the original 

 yellow when neglected ; and in doing 

 so it is interesting to note how the 

 primal colour lingers longest at the 

 base of the petals, thus in the retro- 

 grading white blossoms the tube of the 

 corolla retains for several successive 

 years a dark purple hue, exactly as we 

 saw the yellow loiter in the claw of the 

 advancing water crowfoot. 



In contrast with the acrid, biting 

 character of the majority of the crow* 



